Conventional silicone fluids (trimethylsiloxy-terminated polydimethylsiloxanes) are widely used as lubricants and release aids, as well as cooling and heating media in numerous industrial applications. These fluids may be used at 150.degree. C. continuously in air for long periods of time, without significantly losing their useful properties; however, at about 200.degree. C. or above, oxidative thermal aging takes place, and the fluids gradually turn into gels.
Many antiaging agents, such as substituted catechols, p-aminophenol, diphenylamine, 2-phenylhydroquinone, naphthols, metal chelate compounds, particularly the acetylacetonates of numerous heavy metals, pyrene, and iron octoate, have been used as additives for preventing or postponing the process of gellation of PDMS oils at elevated temperatures, but most of these compounds are difficult to incorporate uniformly, and often form undesirable oxidized by-products.
U.S. Pat. No. 4,185,140 discloses the use for fuser members of polymeric release agents having functional groups such as carboxy, hydroxy, epoxy, amino, isocyanate, thioether or mercapto groups. The functional polymeric fluids interact with the fuser member to strongly attach to the fuser member to prevent toner from contacting the fuser member.
U.S. Pat. No. 5,395,725 discloses the blend of at least one mercapto-functionalized silicone oil with at least one non-mercapto-functionalized silicone oil to minimize volatile emissions from the silicone oil.
Therefore, a need exists for providing improved release agents which can be used at elevated temperatures without producing insoluble or undesirable by-products or gellation.